From 092d3ab0752c60cb6cf91dde9595e14d6d3586da Mon Sep 17 00:00:00 2001
From: tarodx <janderfm@gmail.com>
Date: Sun, 20 Apr 2014 00:00:37 +0200
Subject: [PATCH] Inverse of a matrix

This code calculates the inverse of a matrix and cache it in memory for
use it in the future if it is needed.
---
 cachematrix.R | 67 +++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 57 insertions(+), 10 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..f10ba9e742f 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,62 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
+## This function creates a list type object with lenght 4.
+## Each of the list elements is a function for set/get the
+## original or the inverse matrix
 makeCacheMatrix <- function(x = matrix()) {
-
+        
+        ## Initialize inv matrix: first time it has a NULL value
+        inv <- NULL 
+        
+        ## Define set and get matrix functions
+        
+        ## Setmatrix
+        setmatrix <- function(y){
+                x <<- y
+                inv <<- NULL
+        }
+        
+        ## Getmatrix: Return the original matrix
+        getmatrix <- function() x
+        
+        ## Define set and get inverse matrix functions
+        
+        ## Setinverse
+        setinverse <- function(solve) inv <<- solve
+        
+        ## Getinverse: Return the inverse matrix
+        getinverse <- function() inv
+        
+        ## Define the list variable with all the available operations
+        list(setmatrix = setmatrix, getmatrix = getmatrix, 
+             setinverse = setinverse, getinverse = getinverse)
 }
 
-
-## Write a short comment describing this function
-
+## This function returns the inverse of a defined matrix.
+## If it is the first time the function is called, it calculates
+## the inverse of the matrix and return its value, and cached it in memory.
+## If the function is called more than one times, the function used the
+## cache value and return it instead of calculated it again.
 cacheSolve <- function(x, ...) {
+        
         ## Return a matrix that is the inverse of 'x'
-}
+        
+        ## Get the inverse of the "x" matrix by calling the getinverse function
+        inv <- x$getinverse()
+        
+        ## If is not null "inv" then return the cached value
+        if(!is.null(inv)){
+                message("getting cached inverse")
+                
+                ## If the inverse is cached, return it instead of calculate it.
+                return(inv)
+        }
+        
+        ## Get the original "x" matrix by calling the getmatrix function
+        data <- x$getmatrix()
+        
+        ## Set the inverse of the "x" matrix
+        inv <- solve(data, ...)
+        x$setinverse(inv)
+        
+        ## Return the inverse of the matrix (if it is not in cache)
+        inv
+}
\ No newline at end of file